92 lines
1.8 KiB
ArmAsm
92 lines
1.8 KiB
ArmAsm
#
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/*
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* Raspberry Pi support library for the ACK
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* © 2013 David Given
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* This file is redistributable under the terms of the 3-clause BSD license.
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* See the file 'Copying' in the root of the distribution for the full text.
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*/
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! Declare segments (the order is important).
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.sect .text
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.sect .rom
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.sect .data
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.sect .bss
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.sect .text
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#define gp r15
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begtext:
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! Set up system registers.
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lea gp, begtext
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st sp, .returnsp
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st lr, .returnlr
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! The GPU kernel code will load parameters into r0-r5. Save them
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! so that the user code can access them.
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sub r0, gp ! pointer
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sub r1, gp ! pointer
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sub r2, gp ! pointer
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sub r3, gp ! pointer
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! r4-r5 are not pointers and don't need adjusting
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push r0-r5
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sub r0, sp, gp
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st r0, _gpu_parameters
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! Wipe the bss. (I'm a little suprised that __m_a_i_n doesn't do this.)
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lea r0, begbss
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lea r1, endbss
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mov r2, #0
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_1:
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stb r2, (r0)
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addcmpb.lt r2, #1, r1, _1
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! Push standard parameters onto the stack and go.
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mov r0, #0
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push r0 ! envp
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push r0 ! argv
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push r0 ! argc
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! Call the language startup code.
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bl __m_a_i_n
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! Fall through to __exit if this returns.
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.define __exit
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__exit:
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ld sp, .returnsp
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ld lr, .returnlr
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b lr
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! Define symbols at the beginning of our various segments, so that we can find
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! them. (Except .text, which has already been done.)
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.define begtext, begdata, begbss
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.sect .data; begdata:
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.sect .rom; begrom:
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.sect .bss; begbss:
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! Some magic data. All EM systems need these.
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.define .trppc, .ignmask, _errno
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.comm .trppc, 4
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.comm .ignmask, 4
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.comm _errno, 4
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! We store the stack pointer and return address on entry so that we can
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! cleanly exit.
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.comm .returnsp, 4
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.comm .returnlr, 4
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! User pointer to the GPU kernel parameter block.
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.define _gpu_parameters
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.comm _gpu_parameters, 4
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